AJR. American journal of roentgenology
-
In this review, we attempt to address many of the issues that are related to ensuring patient benefit in body CT, balancing the use of ionizing radiation and iodinated contrast media. We attempt to not only summarize the literature but also make recommendations relevant to CT protocols, including the technical parameters of both the scanner and the associated contrast media. ⋯ Although CT is a powerful tool that has transformed the practice of medicine, the benefits are accompanied by important risks. Radiologists must understand these risks and the strategies available to minimize them as well as the risks associated with contrast medium delivery in abdominal CT.
-
AJR Am J Roentgenol · Jul 2011
ReviewMR enterography of Crohn disease: part 1, rationale, technique, and pitfalls.
The purpose of this article is to review the technique of performing MR enterography examinations and to review the imaging findings suggestive of Crohn disease. This article will also allow the reader to self-assess and improve his or her skills in the performance and interpretation of MR enterography examinations. ⋯ MRI plays a valuable role in providing accurate information about the severity of and complications related to Crohn disease and can help in guiding surgical or medical treatment.
-
The purpose of this article is to review some of the most common reasons for ultrasound intervention around the hip joint, and describe the techniques involved. ⋯ Ultrasound alleviates the need for exposure to radiation and is already the modality of choice for aspiration of the hip joint, an intervention that may be helpful in guiding antimicrobial therapy and help avoid the need for surgical intervention. Ultrasound can also be used to access the hip for diagnostic or therapeutic injection.
-
This article will illustrate and describe the spectrum of diseases associated with air cysts at high-resolution CT (HRCT). ⋯ HRCT is an important modality in the evaluation of interstitial lung disease to include cystic lung disease. Although most commonly associated with lymphangioleiomyomatosis or Langerhans cell histiocytosis, cystic lung disease is increasingly being recognized as a feature of other entities. Awareness of the spectrum of HRCT findings associated with these diseases may help the trained observer narrow the differential diagnosis.
-
AJR Am J Roentgenol · Jun 2011
ReviewIntravoxel incoherent motion in body diffusion-weighted MRI: reality and challenges.
Diffusion-weighted MRI is increasingly applied in the body. It has been recognized for some time, on the basis of scientific experiments and studies in the brain, that the calculation of apparent diffusion coefficient by simple monoexponential relationship between MRI signal and b value does not fully account for tissue behavior. However, appreciation of this fact in body diffusion MRI is relatively new, because technologic advancements have only recently enabled high-quality body diffusion-weighted images to be acquired using multiple b values. There is now increasing interest in the radiologic community to apply more sophisticated analytic approaches, such as those based on the principles of intravoxel incoherent motion, which allows quantitative parameters that reflect tissue microcapillary perfusion and tissue diffusivity to be derived. ⋯ In this review, we discuss the principles of intravoxel incoherent motion as applied to body diffusion-weighted MRI. The evidence for the technique in measuring tissue perfusion is presented and the emerging clinical utility surveyed. The requisites and challenges of quantitative evaluation beyond simple monoexponential relationships are highlighted.